A shear panel is a wall in a structure which is designed to counteract lateral stress, ensuring that the structure remains sound even when it is subjected to violent shearing motions. Lateral shear is especially common in earthquakes, when structures are whipped back and forth as the ground moves, and it is also caused by high winds, particularly in the case of tall buildings. Many building codes around the world require the use of shear panels in construction for safety.
Shear panels are also known as shear walls or braced panels. They are constructed by bolting a number of lateral supports to the external framing of a building, along with the internal joists in the floor and roof. These supports stabilize the structure, and when covered by a wall, they turn into a solid reinforcing wall which will resist lateral shear. The strength of resistance depends on the size of the structure, the width of the shear panel, and the construction materials used.
In order to be effective, a shear panel must be both strong and stiff. Strong walls are important, to resist the tearing forces involved with lateral sheer. Stiffness is also critical, to ensure that the shear panel holds its position in addition to remaining intact. The amount of strength and stiffness needed can be calculated by an engineer or architect to determine whether or not the shear panel will do its job. Shear walls can be load bearing or non-load bearing, but in both cases, they are critical to the structural integrity of the building.
Many building codes err on the side of caution, which is why shear panels are required even in regions where high winds and earthquakes are rare. Freak weather conditions do happen, and it is better to be prepared for an event which never happens than to be underprepared for a devastating earthquake or storm. When constructing shear panels, contractors also need to think about how the space is going to be used, because they want to provide structural support without infringing upon the usability of the space.
Windows and doors do not provide resistance against shear forces, and therefore, structures built with lots of windows need to be constructed very carefully. The use of many windows may require more shear panels than would otherwise be needed, with the goal of creating a strong core to support the building in the event that severe shear forces occur. Especially in the case of large buildings, it is always a good idea to get an additional engineering firm to look over the plans to check for any design flaws or overlooked safety features.